Popocatepetl

Mexico

19.023°N, 98.622°W; summit elev. 5393 m

All times are local (unless otherwise noted)

At 2113 on 24 March activity at Popocatépetl increased and a four-hour series of explosions produced steam, gas, and ash emissions that rose 3 km. Incandescent tephra was ejected 800 m onto the NE and SE flanks. The last explosion in the series was detected at 0118 on 25 March. Additional explosion on 25 March ejected tephra and generated steam, gas, and ash plumes; the plumes rose 2 km and drifted NE and SE causing ashfall in Atlixco, Puebla. During 26-31 March the seismic network recorded between 21 and 86 emissions per day that sometimes contained ash. Cloud cover often prevented observations of the crater, although ash plumes and nighttime crater incandescence were noted. Continuous steam, gas, and ash emissions on 26 March rose 600 m and drifted ENE. On 29 March at 0944 an ash plume rose 2 km. On 31 March one of three explosions, which occurred at 0740, generated an ash plume that rose less than 1 km and drifted SW. The Alert Level remained at Yellow, Phase Two.

Geologic Background. Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, rises 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major Plinian eruptions, the most recent of which took place about 800 CE, have occurred since the mid-Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since Pre-Columbian time.